Refrigerator and control method thereof

ABSTRACT

A refrigerator, the temperature of the inside of which is uniformly controlled, and a control method thereof. The direction of an air flow in a storage chamber is periodically changed so as to uniformly distribute cool air in the storage chamber by interchanging roles of suction and discharge holes in various manners under various conditions, thereby preventing local supercooling and thus uniformly maintaining the internal temperature of the storage chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No.2010-0132638, filed on Dec. 22, 2010 in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field

Embodiments relate to a refrigerator, the temperature of the inside ofwhich is uniformly controlled, and a control method thereof.

2. Description of the Related Art

In general, a refrigerator is an apparatus which supplies cool airgenerated through a refrigerating cycle of a refrigerant to food storagechambers, such as a freezing chamber and a refrigerating chamber, so asto store food in a fresh state for a long time. Recently, a kimchirefrigerator to ferment and store kimchi using such a refrigeratorprinciple has been developed.

Kimchi is fermented food using fermentation of microorganisms as well assalted food having increased preservation using salt, and a rate atwhich fermentation of kimchi proceeds is varied according to salinityand temperature of kimchi. Ripening and storing temperatures of kimchistored in a storage chamber are set based on standard kimchi. A salinityvalue of the standard kimchi is generally in the range of about 2.2%.

A salinity value of kimchi deviates from the salinity value range of thestandard kimchi according to regions in which kimchi is consumed,seasons and kinds of kimchi and respective family tastes. If thesalinity of kimchi is lower than that of the standard kimchi, moistureor juice in kimchi tissue is frozen. That is, when a kimchi container isstored in the storage chamber, local supercooling in which kimchilocated close to a discharge hole to discharge cool air is frozen occursdue to a narrow channel space within the storage chamber, and kimchilocated close to a suction hole to suck air is more rapidly ripened andpreservation of the taste of well-ripened kimchi is difficult. Sinceroles of the suction hole and the discharge hole to form an air flow arefixed, the air flow in the storage chamber is not uniformly distributed.

SUMMARY

Therefore, it is an aspect to provide a refrigerator, in which a flow ofcool air in a storage chamber is uniformly distributed so as to preventlocal supercooling and to uniformly maintain internal temperature of thestorage chamber by interchanging roles of suction and discharge holes invarious manners under various conditions, and a control method thereof.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the invention.

In accordance with one aspect, a refrigerator includes a storagechamber, an evaporator to cool air in the storage chamber, a firstopening to suck the air in the storage chamber, a second opening todischarge the air cooled by the evaporator to the inside of the storagechamber, a fan provided with blades, which are driven at a first angleand a second angle, and a control unit to adjust the direction of a flowof the air by driving the fan at the first angle so that the air in thestorage chamber is sucked through the first opening and is thendischarged to the inside of the storage chamber through the secondopening and by driving the fan at the second angle so that the air inthe storage chamber is sucked through the second opening and is thendischarged to the inside of the storage chamber through the firstopening.

The first angle and the second angle may be blade angles having reversedelta values.

The control unit may drive the fan at the first angle or the secondangle so as to periodically change the direction of the air flow.

in accordance with another aspect, a refrigerator includes a storagechamber, an evaporator to cool air in the storage chamber, a firstopening to suck the air in the storage chamber, a second opening todischarge the air cooled by the evaporator to the inside of the storagechamber, first and second fans to respectively generate flows of the airin opposite directions, and a control unit to adjust the direction ofthe air flow by driving the first fan so that the air in the storagechamber is sucked through the first opening and is then discharged tothe inside of the storage chamber through the second opening and bydriving the second fan so that the air in the storage chamber is suckedthrough the second opening and is then discharged to the inside of thestorage chamber through the first opening.

The first fan and the second fan may have blade angles having reversevalues.

The control unit may drive the first and second fans so as toperiodically change the direction of the air flow.

In accordance with another aspect, a refrigerator includes a storagechamber, an evaporator to cool air in the storage chamber, a pair offirst openings to suck the air in the storage chamber, a pair of secondopenings to discharge the air cooled by the evaporator to the inside ofthe storage chamber, first and second ducts respectively connecting thepair of first openings and the pair of second openings to form airchannels in the storage chamber, first and second dampers installed inthe first and second ducts to permit or block the air flow toward one ofthe first and second ducts, and a control unit to adjust the directionof the air flow by controlling the first and second dampers so that theair flows toward one of the first and second ducts.

The first and second dampers may be installed at an intersection betweenthe first and second ducts.

The control unit may drive the first and second dampers so as toperiodically change the direction of the air flow.

The refrigerator may further include a third duct at which the firstduct and the second duct meet, and the evaporator and a fan may beinstalled in the third duct.

The pair of first openings and the pair of second openings may berespectively installed at upper and lower portions of the rear surfaceof the storage chamber.

The pair of first openings and the pair of second openings may berespectively installed at both side surfaces of the storage chamber.

In accordance with another aspect, a control method of a refrigerator,which has a storage chamber, a first opening to suck the air in thestorage chamber, a second opening to discharge the air to the inside ofthe storage chamber, and a fan provided with blades, the angle of whichis varied, to generate a flow of the air, includes driving the fan at afirst angle of the blades so that the air in the storage chamber issucked through the first opening and is then discharged to the inside ofthe storage chamber through the second opening, judging whether or not adesignated time has elapsed, and driving the fan at a second angle ofthe blades so that the air in the storage chamber is sucked through thesecond opening and is then discharged to the inside of the storagechamber through the first opening, upon judging that the designated timehas elapsed.

The driving of the fan at the first angle of the blades and the drivingof the fan at the second angle of the blades may be periodicallyalternated so as to uniformly distribute the air flow throughout theoverall space of the storage chamber.

In accordance with another aspect, a control method of a refrigerator,which has a storage chamber, a first opening to suck the air in thestorage chamber, a second opening to discharge the air to the inside ofthe storage chamber, and first and second fans to respectively generateflows of the air in opposite directions, includes driving the first fanso that the air in the storage chamber is sucked through the firstopening and is then discharged to the inside of the storage chamberthrough the second opening, judging whether or not a designated time haselapsed, and driving the second fan so that the air in the storagechamber is sucked through the second opening and is then discharged tothe inside of the storage chamber through the first opening, uponjudging that the designated time has elapsed.

The driving of the first fan and the driving of the second fan may beperiodically alternated so as to uniformly distribute the air flowthroughout the overall space of the storage chamber.

In accordance with a further aspect, a control method of a refrigerator,which has a storage chamber, a pair of first openings to suck the air inthe storage chamber, a pair of second openings to discharge the air tothe inside of the storage chamber, first and second ducts respectivelyconnecting the pair of first openings and the pair of second openings toform air channels in the storage chamber, and first and second dampersinstalled in the first and second ducts to permit or block the air flowtoward one of the first and second ducts, includes driving the first andsecond dampers so that the air flows toward one of the first and secondducts, judging whether or not a designated time has elapsed, and drivingthe first and second dampers so that the air flows toward the other oneof the first and second ducts, upon judging that the designated time haselapsed.

The driving of the first and second dampers so that the air flows towardone of the first and second ducts and the driving of the first andsecond dampers so that the air flows toward the other one of the firstand second ducts may be periodically alternated so as to uniformlydistribute the air flow throughout the overall space of the storagechamber.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of the invention will become apparent andmore readily appreciated from the following description of theembodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a perspective view illustrating a configuration of arefrigerator applied to one embodiment;

FIG. 2 is a cross-sectional view illustrating a first storage chamber ofthe refrigerator in accordance with the embodiment;

FIG. 3 is a control block diagram of the refrigerator in accordance withthe embodiment;

FIG. 4 is a flow chart illustrating an algorithm to control an air flowof the refrigerator in accordance with the embodiment;

FIG. 5 is a cross-sectional view illustrating an upward direction of theair flow of the refrigerator in accordance with the embodiment;

FIG. 6 is a cross-sectional view illustrating a downward direction ofthe air flow of the refrigerator in accordance with the embodiment;

FIGS. 7A and 7B are views illustrating a structure of a fan with avaried blade angle to change the direction of the air flow of therefrigerator in accordance with the embodiment;

FIG. 8 is a cross-sectional view illustrating a first storage chamber ofa refrigerator in accordance with another embodiment;

FIG. 9 is a control block diagram of the refrigerator in accordance withthe embodiment;

FIG. 10 is a flow chart illustrating an algorithm to control an air flowof the refrigerator in accordance with the embodiment;

FIG. 11 is a cross-sectional view illustrating an upward direction ofthe air flow of the refrigerator in accordance with the embodiment;

FIG. 12 is a cross-sectional view illustrating a downward direction ofthe air flow of the refrigerator in accordance with the embodiment;

FIG. 13 is a cross-sectional view illustrating a first storage chamberof a refrigerator in accordance with another embodiment;

FIG. 14 is a control block diagram of the refrigerator in accordancewith the embodiment;

FIG. 15 is a flow chart illustrating an algorithm to control an air flowof the refrigerator in accordance with the embodiment;

FIG. 16 is a cross-sectional view illustrating an upward direction ofthe air flow of the refrigerator in accordance with the embodiment; and

FIG. 17 is a cross-sectional view illustrating a downward direction ofthe air flow of the refrigerator in accordance with the embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments, examples ofwhich are illustrated in the accompanying drawings, wherein likereference numerals refer to like elements throughout.

FIG. 1 is a perspective view illustrating a configuration of arefrigerator applied to one embodiment.

As shown in FIG. 1, a refrigerator 1 in accordance with this embodimentincludes a box-shaped main body 10 forming the external appearance ofthe refrigerator 1, a plurality of storage chambers 21, 22 and 23 formedin the main body 10 to store food, and doors 31, 32 and 33 connected tothe main body 10 to open and close the plurality of storage chambers 21,22 and 23.

The plurality of storage chambers 21, 22 and 23 is vertically dividedinto a first storage chamber 21, a second storage chamber 22 and a thirdstorage chamber 23 by diaphragms. The first storage chamber 21, thesecond storage chamber 22 and the third storage chamber 23 respectivelyform independent storage spaces, and storage temperatures of the storagechambers 21, 22 and 23 are independently controlled according to amountsof cool air supplied to the respective storage chambers 21, 22 and 23.

Further, the first storage chamber 21 is divided into plural spaces byplural shelves such that food may be put on the respective shelves. Afirst opening (hereinafter, referred to as a ‘suction hole’) 24 and asecond opening (hereinafter, referred to as a ‘discharge hole’) 25 toform an air flow at the inside of the first storage chamber 21 areformed through the rear surface of the first storage chamber 21.

The suction hole 24 is provided at the lower portion of the rear surfaceof the first storage chamber 21 so as to suck air in the first storagechamber 21, and the discharge hole 25 is provided at the upper portionof the rear surface of the first storage chamber 21 so as to dischargecool air to the inside of the first storage chamber 21.

Further, a temperature sensor 26 to sense a temperature in the firststorage chamber 21 is installed at the lower portion of the rear surfaceof the first storage chamber 21.

The doors 31, 32 and 33 include a rotating door 31 rotatably connectedto the main body 10 so as to open and close the first storage chamber21, and drawer-type doors 32 and 33 slidably connected to the main body10 so as to open and close the second storage chamber 22 and the thirdstorage chamber 23.

FIG. 2 is a cross-sectional view illustrating the first storage chamberof the refrigerator in accordance with the embodiment.

As shown in FIG. 2, an evaporator 27 to cool air of the first storagechamber 21 is installed at the rear portion of the inside of the firststorage chamber 21, and a fan 28 to circulate air to the inside of thefirst storage chamber 21 is installed above the evaporator 27.

The fan 28 is a blade fan having a delta angle. Roles of the suctionhole 24 and the discharge hole 25 may be interchanged by varying theangle of blades of the fan 28.

For example, if the fan 28 is driven at the current delta angle of theblades (hereinafter, referred to as a first angle), the suction hole 24formed at the lower portion of the rear surface of the first storagechamber 21 serves to suck air, as it is, and the discharge hole 25formed at the upper portion of the rear surface of the first storagechamber 21 serves to discharge cool air, as it is.

On the other hand, if the fan 28 is driven at the reverse delta angle ofthe blades (hereinafter, referred to as a second angle), the dischargehole 25 formed at the upper portion of the rear surface of the firststorage chamber 21 serves to suck air and the suction hole 24 formed atthe lower portion of the rear surface of the first storage chamber 21serves to discharge cool air.

That is, roles of the suction hole 24 and the discharge hole 25 formedat the lower and upper portions of the rear surface of the first storagechamber 21 are not fixed, but may be interchanged by varying the bladeangle of the fan 28.

FIG. 3 is a control block diagram of the refrigerator in accordance withthe embodiment. The refrigerator includes the temperature sensor 26, aninput unit 50, a control unit 52, a fan drive unit 54 and a display unit58.

The input unit 50 serves to input user's control command to the controlunit 52, and is provided with plural buttons including a start button tostart temperature control of food and a temperature set button to set atemperature at which the food is to be stored.

The control unit 52 is a microcomputer to control the overall operationof the refrigerator 1, and controls driving of the fan 28 so that rolesof the suction hole 24 and the discharge hole 25 are interchanged invarious manners under various conditions.

Conditions to interchange the roles of the suction hole 24 and thedischarge hole 25 include change of the direction of an air flow byvarying the blade angle of the fan 28, as shown in FIG. 2, change of thedirection of an air flow using two fans having reverse blade angles, andchange of the direction or an air flow using dampers.

Hereinafter, interchange of the roles of the suction hole 24 and thedischarge hole 25 by changing the direction of an air flow by varyingthe blade angle of the fan 28 will be described first. Further, changeof the direction of an air flow using two fans having reverse bladeangles and change of the direction of an air flow using dampers will bedescribed later with reference to FIGS. 8 to 17.

First, if the roles of the suction hole 24 and the discharge hole 25 areinterchanged by changing the direction of the air flow by varying theblade angle of the fan 28, the control unit 52 first drives the fan 28at the first angle.

As the fan 28 is driven at the first angle, air in the first storagechamber 21 is sucked through the suction hole 24 formed at the lowerportion of the rear surface of the first storage chamber 21, and thesucked air is cooled into low-humidity and low-temperature air throughthe evaporator 27 and is discharged to the inside of the first storagechamber 21 through the discharge hole 25 formed at the upper portion ofthe rear surface of the first storage chamber 21. Thereby, air flows inthe upward direction.

Thereafter, when a designated time has elapsed (for example, 2 hours),the control unit 52 drives the fan 28 at the second angle.

As the fan 28 is driven at the second angle, air in the first storagechamber 21 sucked through the discharge hole 25 formed at the upperportion of the rear surface of the first storage chamber 21, and thesucked air is cooled into low-humidity and low-temperature air throughthe evaporator 27 and is discharged to the inside of the first storagechamber 21 through the suction hole 24 formed at the lower portion ofthe rear surface of the first storage chamber 21. Thereby, air flows inthe downward direction.

Through the above method in which the control unit 52 alternately drivesthe fan 28 at different angles, i.e., the first angle and the secondangle, every designated time (for example, every 2 hours), air flows inthe upward direction and then flows in the downward direction and thusthe roles of the suction hole 24 and the discharge hole 25 areperiodically interchanged. Thereby, the air flow within the firststorage chamber 21 is uniformly distributed and thus the temperaturewithin the first storage chamber 21 is uniformly maintained.

The fan drive unit 54 controls driving of the fan 28 according to acontrol signal from the control unit 52, thereby varying the blade angleof the fan 28.

The display unit 58 displays an operating state (for example, a kind, aripening time or a temperature condition of food stored in the storagechamber) of the refrigerator 1 or various set values according to acontrol signal from the control unit 52.

Hereinafter, the refrigerator in accordance with this embodiment of thepresent invention, a control method thereof and an operating process,functions and effects thereof will be described with reference to FIGS.4 to 7B.

FIG. 4 is a flow chart illustrating an algorithm to control an air flowof the refrigerator in accordance with this embodiment, FIG. 5 is across-sectional view illustrating an upward direction of the air flow ofthe refrigerator in accordance with this embodiment, FIG. 6 is across-sectional view illustrating a downward direction of the air flowof the refrigerator in accordance with this embodiment, and FIGS. 7A and7B are views illustrating a structure of the fan with a varied bladeangle to change the direction of the air flow of the refrigerator inaccordance with this embodiment.

With reference to FIG. 4, after a user places food to be stored at theinside of the first storage chamber 21, the user inputs a settemperature through the temperature set button provided on the inputunit 50 and then operates the start button, cool air generated by thegeneral refrigerating cycle is supplied to the inside of the firststorage chamber 21 and then starts lowering of the internal temperatureof the storage chamber 21.

Then, in order to uniformly control an air flow (specifically, a coolair flow) in the first storage chamber 21, the control unit 52 drivesthe fan 28 at the first angle, as shown in FIG. 7A, through the fandrive unit 54 (Operation 100).

The fan 28 is driven under the condition that the angle of respectiveblades 30 is set to the first angle, as shown in FIG. 7A, by connectinginner parts of the respective blades 30 to a motor (not shown) of thefan drive unit 54, specifically a motor rotating shaft 30 a provided toconvert the angle of the blades 30 separately from a fan rotating motor,and then rotating the motor by a desired degree.

The fan drive unit 54 controls driving of the fan 28 according to thecontrol signal from the control unit 52, thereby setting the blade angleof the fan 28 to the first angle, as shown in FIG. 7A.

When the fan 28 is driven at the first angle, air flows in the upwarddirection, as shown in FIG. 5. Thereby, air in the first storage chamber21 is sucked through the suction hole 24 formed at the lower portion ofthe rear surface of the first storage chamber 21, and the sucked air iscooled into low-humidity and low-temperature air through the evaporator27 and is discharged to the inside of the first storage chamber 21through the discharge hole 25 formed at the upper portion of the rearsurface of the first storage chamber 21.

Then, the control unit 52 counts time for which the fan 28 is driven atthe first angle (Operation 102), and judges whether or not a designatedtime (for example, 2 hours) has elapsed (Operation 104).

As a result of the judgment of Operation 104, if the designated time hasnot elapsed, the process is fed back to Operation 102 and the controlunit 52 counts time until the designated time has elapsed.

On the other hand, as the result of the judgment of Operation 104, ifthe designated time has elapsed, the control unit 52 drives the fan 28at the second angle, as shown in FIG. 7B, through the fan drive unit 54(Operation 106).

Here, the fan 28 is driven under the condition that the angle of therespective blades 30 is set to the second angle, as shown in FIG. 7B, byconnecting the inner parts of respective blades 30 to the motor rotatingshaft 30 a of the motor (not shown) of the fan drive unit 54 and thenrotating the motor by a desired degree.

When the fan 28 is driven at the second angle, air flows in the downwarddirection, as shown in FIG. 6. Thereby, air in the first storage chamber21 is sucked through the discharge hole 25 formed at the upper portionof the rear surface of the first storage chamber 21, and the sucked airis cooled into low-humidity and low-temperature air through theevaporator 27 and is discharged to the inside of the first storagechamber 21 through the suction hole 24 formed at the lower portion ofthe rear surface of the first storage chamber 21.

Then, the control unit 52 counts time for which the fan 28 is driven atthe second angle (Operation 108), and judges whether or not a designatedtime has elapsed (Operation 110).

As a result of the judgment of Operation 110, if the designated time hasnot elapsed, the process is fed back to Operation 108 and the controlunit 52 counts time until the designated time has elapsed.

On the other hand, as the result of the judgment of Operation 110, ifthe designated time has elapsed, the process is fed back to Operation100 and the control unit 52 drives the fan 28 at the first angle throughthe fan drive unit 54.

Through the above method, air flows in the upward direction, flows inthe downward direction and then flows in the upward direction and thusthe roles of the suction hole 24 and the discharge hole 25 areperiodically interchanged. Thereby, cool air in the first storagechamber 21 is uniformly distributed and thus the temperature within thefirst storage chamber 21 is uniformly maintained.

FIG. 8 is a cross-sectional view illustrating a first storage chamber ofa refrigerator in accordance with another embodiment. Some parts in thisembodiment shown in FIG. 8, which are substantially the same as those inthe embodiment shown in FIG. 2, are denoted by the same referencenumerals even though they are depicted in different drawings, and adetailed description thereof will thus be omitted because it isconsidered to be unnecessary.

As shown in FIG. 8, an evaporator 27 to cool air of the first storagechamber 21 is installed at the rear portion of the inside of the firststorage chamber 21, and first and second fans 29 a and 29 b to circulateair to the inside of the first storage chamber 21 are installed abovethe evaporator 27.

The first and second fans 29 a and 29 b are blade fans having reversedelta angles. Roles of the suction hole 24 and the discharge hole 25 maybe interchanged by respectively driving the first and second fans 29 aand 29 b.

For example, if the first fan 29 a is driven, the suction hole 24 formedat the lower portion of the rear surface of the first storage chamber 21serves to suck air in the first storage chamber 21, as it is, and thedischarge hole 25 formed at the upper portion of the rear surface of thefirst storage chamber 21 serves to discharge cool air to the inside ofthe first storage chamber 21, as it is.

On the other hand, if the second fan 29 b is driven, the discharge hole25 formed at the upper portion of the rear surface of the first storagechamber 21 serves to suck air in the first storage chamber 21 and thesuction hole 24 formed at the lower portion of the rear surface of thefirst storage chamber 21 serves to discharge cool air to the inside ofthe first storage chamber 21.

That is, the roles of the suction hole 24 and the discharge hole 25formed at the lower and upper portions of the rear surface of the firststorage chamber 21 are not fixed, but may be interchanged according towhether or not the first and second fans 29 a and 29 b are driven.

FIG. 9 is a control block diagram of the refrigerator in accordance withthis embodiment. Some parts in this embodiment shown in FIG. 9, whichare substantially the same as those in the embodiment shown in FIG. 3,are denoted by the same reference numerals even though they are depictedin different drawings, and a detailed description thereof will thus beomitted because it is considered to be unnecessary.

The control unit 52 is a microcomputer to control the overall operationof the refrigerator 1, and controls driving of the first and second fans29 a and 29 b so that the roles of the suction hole 24 and the dischargehole 25 are interchanged in various manners under various conditions.

Here, a condition to interchange the roles of the suction hole 24 andthe discharge hole 25 is change of the direction of an air flow usingthe first and second fans 29 a and 29 b having reverse blade angles.

First, the control unit 52 drives the first fan 29 a.

As the first fan 29 a is driven, air in the first storage chamber 21 issucked through the suction hole 24 formed at the lower portion of therear surface of the first storage chamber 21, and the sucked air iscooled into low-humidity and low-temperature air through the evaporator27 and is discharged to the inside of the first storage chamber 21through the discharge hole 25 formed at the upper portion of the rearsurface of the first storage chamber 21. Thereby, air flows in theupward direction.

Thereafter, if a designated time (for example, 2 hours) has elapsed, thecontrol unit 52 drives the second fan 29 b.

As the second fan 29 b is driven, air in the first storage chamber 21 issucked through the discharge hole 25 formed at the upper portion of therear surface of the first storage chamber 21, and the sucked air iscooled into low-humidity and low-temperature air through the evaporator27 and is discharged to the inside of the first storage chamber 21through the suction hole 24 formed at the lower portion of the rearsurface of the first storage chamber 21. Thereby, air flows in thedownward direction.

Through the above method in which the control unit 52 alternately drivesthe first and second fans 29 a and 29 b every designated time (forexample, every 2 hours), air flows in the upward direction and thenflows in the downward direction and thus the roles of the suction hole24 and the discharge hole 25 are periodically interchanged. Thereby, theair flow within the first storage chamber 21 is uniformly distributedand thus the temperature within the first storage chamber 21 isuniformly maintained.

The fan drive unit 54 controls driving of the first and second fans 29 aand 29 b according to a control signal from the control unit 52, therebyalternately driving the first and second fans 29 a and 29 b.

Hereinafter, the refrigerator in accordance with this embodiment of thepresent invention, a control method thereof and an operating process,functions and effects thereof will be described with reference to FIGS.10 to 12.

FIG. 10 is a flow chart illustrating an algorithm to control an air flowof the refrigerator in accordance with this embodiment, FIG. 11 is across-sectional view illustrating an upward direction of the air flow ofthe refrigerator in accordance with this embodiment, and FIG. 12 is across-sectional view illustrating a downward direction of the air flowof the refrigerator in accordance with this embodiment.

With reference to FIG. 10, in order to uniformly control an air flow(specifically, a cool air flow) in the first storage chamber 21, thecontrol unit 52 drives the first fan 29 a through the fan drive unit 54(Operation 200).

When the first fan 29 a is driven, air flows in the upward direction, asshown in FIG. 11. Thereby, air in the first storage chamber 21 is suckedthrough the suction hole 24 formed at the lower portion of the rearsurface of the first storage chamber 21, and the sucked air is cooledinto low-humidity and low-temperature air through the evaporator 27 andis discharged to the inside of the first storage chamber 21 through thedischarge hole 25 formed at the upper portion of the rear surface of thefirst storage chamber 21.

Then, the control unit 52 counts time for which the first fan 29 a isdriven (Operation 202), and judges whether or not a designated time haselapsed (Operation 204).

As a result of the judgment of Operation 204, if the designated time hasnot elapsed, the process is fed back to Operation 202 and the controlunit 52 counts time until the designated time has elapsed.

On the other hand, as the result of the judgment of Operation 204, ifthe designated time has elapsed, the control unit 52 drives the secondfan 29 b through the fan drive unit 54 (Operation 206).

When the second fan 29 b is driven, air flows in the downward direction,as shown in FIG. 12. Thereby, air in the first storage chamber 21 issucked through the discharge hole 25 formed at the upper portion of therear surface of the first storage chamber 21, and the sucked air iscooled into low-humidity and low-temperature air through the evaporator27 and is discharged to the inside of the first storage chamber 21through the suction hole 24 formed at the lower portion of the rearsurface of the first storage chamber 21.

Then, the control unit 52 counts time for which the second fan 29 b isdriven (Operation 208), and judges whether or not a designated time haselapsed (Operation 210).

As a result of the judgment of Operation 210, if the designated time hasnot elapsed, the process is fed back to Operation 208 and the controlunit 52 counts time until the designated time has elapsed.

On the other hand, as the result of the judgment of Operation 210, ifthe designated time has elapsed, the process is fed back to Operation200 and the control unit 52 drives the first fan 29 a through the fandrive unit 54.

Through the above method, air flows in the upward direction, flows inthe downward direction and then flows in the upward direction and thusthe roles of the suction hole 24 and the discharge hole 25 areperiodically interchanged. Thereby, cool air in the first storagechamber 21 is uniformly distributed and thus the temperature within thefirst storage chamber 21 is uniformly maintained.

FIG. 13 is a cross-sectional view illustrating a first storage chamberof a refrigerator in accordance with another embodiment. Some parts inthis embodiment shown in FIG. 13, which are substantially the same asthose in the embodiment shown in FIG. 2, are denoted by the samereference numerals even though they are depicted in different drawings,and a detailed description thereof will thus be omitted because it isconsidered to be unnecessary.

As shown in FIG. 13, two suction holes 24 a and 24 b and two dischargeholes 25 a and 25 b to induce an air flow in the first storage chamber21 are formed on the rear surface of the first storage chamber 21.

The suction holes 24 a and 24 b are provided at the upper and lowerportions of the rear surface of the first storage chamber 21 so as tosuck air in the first storage chamber 21, and the discharge holes 25 aand 25 b are provided at the upper and lower portions of the rearsurface of the first storage chamber 21 so as to discharge cool air tothe inside of the first storage chamber 21.

Further, two ducts, i.e., first and second ducts 41 and 42, which areextended in the vertical direction to uniformly distribute airthroughout the overall space of the first storage chamber 21 areinstalled at the rear portion of the inside of the first storage chamber21, and a third duct 43 to change the direction of the air flow isinstalled at an intersection between the first and second ducts 41 and42.

An evaporator 27 to cool air of the first storage chamber 21 and a fan28 to circulate the air of the first storage chamber 21 are installedwithin the third duct 43.

First and second dampers 45 and 46 to adjust the direction of the airflow so as to allow air circulated by the fan 28 to move toward thefirst duct 41 or the second duct 42 are installed at both ends of thethird duct 43 connected with the first and second ducts 41 and 42.

The first and second dampers 45 and 46 are driven by damper motors (notshown), thereby changing the direction of the air flow and thusinterchanging roles of the suction holes 24 a and 24 b and the dischargeholes 25 a and 25 b.

For example, if the first and second dampers 45 and 46 are driven sothat an air channel connected with the first duct 41 is completelyclosed and an air channel connected with the second duct 42 iscompletely opened, the suction hole 24 a formed at the lower portion ofthe left side of the rear surface of the first storage chamber 21 servesto suck air in the first storage chamber 21 and the discharge hole 25 aformed at the upper portion of the right side of the rear surface of thefirst storage chamber 21 serves to discharge cool air to the inside ofthe first storage chamber 21. Thereby, air flows in the upwarddirection.

On the other hand, if the first and second dampers 45 and 46 are drivenso that the air channel connected with the first duct 41 is completelyopened and the air channel connected with the second duct 42 iscompletely closed, the suction hole 24 b formed at the upper portion ofthe left side of the rear surface of the first storage chamber 21 servesto suck air in the first storage chamber 21 and the discharge hole 25 bformed at the lower portion of the right side of the rear surface of thefirst storage chamber 21 serves to discharge cool air to the inside ofthe first storage chamber 21. Thereby, air flows in the downwarddirection.

That is, the roles of the suction holes 24 a and 24 b and the dischargeholes 25 a and 15 b respectively formed at the upper and lower portionsof the rear surface of the first storage chamber 21 are not fixed, butmay be interchanged according to whether or not the first and seconddampers 45 and 46 are driven.

Although this embodiment illustrates that a pair of suction holes 24 aand 24 b and a pair of discharge holes 25 a and 25 b are installed atthe upper and lower portions of the rear surface of the first storagechamber 21, the positions of the suction holes 24 a and 24 and thedischarge holes 25 a and 25 b are not limited thereto. For example, apair of suction holes 24 a and 24 b and a pair of discharge holes 25 aand 25 b may be installed at both side surfaces of the first storagechamber 21 in the same manner.

FIG. 14 is a control block diagram of the refrigerator in accordancewith this embodiment. Some parts in this embodiment shown in FIG. 14,which are substantially the same as those in the embodiment shown inFIG. 3, are denoted by the same reference numerals even though they aredepicted in different drawings, and a detailed description thereof willthus be omitted because it is considered to be unnecessary.

The control unit 52 is a microcomputer to control the overall operationof the refrigerator 1, and controls driving of the first and seconddampers 45 and 46 so that the roles of the suction holes 24 a and 24 band the discharge holes 25 a and 25 b are interchanged in variousmanners under various conditions.

Here, a condition to interchange the roles of the suction holes 24 a and24 b and the discharge holes 25 a and 25 b is change of the direction ofthe air flow using the first and second dampers 45 and 46 to open andclose the air channels of the first and second ducts 41 and 42.

First, the control unit 52 drives the first and second dampers 45 and 46so that the air channel connected with the first duct 41 is completelyclosed and the air channel connected with the second duct 42 iscompletely opened.

As the first and second dampers 45 and 46 are driven, air in the firststorage chamber 21 is sucked through the suction hole 24 a formed at thelower portion of the left side of the rear surface of the first storagechamber 21, and the sucked air is cooled into low-humidity andlow-temperature air through the evaporator 27 and is discharged to theinside of the first storage chamber 21 through the discharge hole 25 aformed at the upper portion of the right side of the rear surface of thefirst storage chamber 21. Thereby, air flows in the upward direction.

Thereafter, if a designated time (for example, 2 hours) has elapsed, thecontrol unit 52 drives the first and second dampers 45 and 46 so thatthe air channel connected with the first duct 41 is completely openedand the air channel connected with the second duct 42 is completelyclosed.

As the first and second dampers 45 and 46 are driven, air in the firststorage chamber 21 is sucked through the suction hole 24 a formed at theupper portion of the left side of the rear surface of the first storagechamber 21, and the sucked air is cooled into low-humidity andlow-temperature air through the evaporator 27 and is discharged to theinside of the first storage chamber 21 through the discharge hole 25 aformed at the lower portion of the right side of the rear surface of thefirst storage chamber 21. Thereby, air flows in the downward direction.

As described above, through the above method in which the control unit52 sequentially drives the first and second dampers 45 and 46 everydesignated time (for example, every 2 hours), air flows in the upwarddirection and then flows in the downward direction and thus the roles ofthe suction holes 24 a and 24 b and the discharge holes 25 a and 25 bare periodically interchanged. Thereby, the air flow within the firststorage chamber 21 is uniformly distributed and thus the temperaturewithin the first storage chamber 21 is uniformly maintained.

A damper drive unit 56 controls driving of the first and second dampers45 and 46 according to a control signal from the control unit 52,thereby changing the direction of the air flow.

Hereinafter, the refrigerator in accordance with this embodiment, acontrol method thereof and an operating process, functions and effectsthereof will be described with reference to FIGS. 15 to 17.

FIG. 15 is a flow chart illustrating an algorithm to control an air flowof the refrigerator in accordance with this embodiment, FIG. 16 is across-sectional view illustrating an upward direction of the air flow ofthe refrigerator in accordance with this embodiment, and FIG. 17 is across-sectional view illustrating a downward direction of the air flowof the refrigerator in accordance with this embodiment.

With reference to FIG. 15, in order to uniformly control an air flow(specifically, a cool air flow) in the first storage chamber 21, thecontrol unit 52 drives the fan 28 through the fan drive unit 54(Operation 300).

Then, the control unit 52 drives the first and second dampers 45 and 46through the damper drive unit 56 so that the air channel connected withthe first duct 41 is completely closed and the air channel connectedwith the second duct 42 is completely opened (Operation 302).

When the first and second dampers 45 and 46 are driven, air flows in theupward direction, as shown in FIG. 16. Thereby, air in the first storagechamber 21 is sucked through the suction hole 24 a formed at the lowerportion of the left side of the rear surface of the first storagechamber 21, and the sucked air is cooled into low-humidity andlow-temperature air through the evaporator 27 and is discharged to theinside of the first storage chamber 21 through the discharge hole 25 aformed at the upper portion of the right side of the rear surface of thefirst storage chamber 21.

Then, the control unit 52 counts time for which the first and seconddampers 45 and 46 are driven so that the air channel of the second duct42 is opened (Operation 304), and judges whether or not a designatedtime has elapsed (Operation 306).

As a result of the judgment of Operation 306, if the designated time hasnot elapsed, the process is fed back to Operation 304 and the controlunit 52 counts time until the designated time has elapsed.

On the other hand, as the result of the judgment of Operation 306, ifthe designated time has elapsed, the control unit 52 drives the firstand second dampers 45 and 46 through the damper drive unit 56 so thatthe air channel connected with the first duct 41 is completely openedand the air channel connected with the second duct 42 is completelyclosed (Operation 308).

When the first and second dampers 45 and 46 are driven, air flows in thedownward direction, as shown in FIG. 17. Thereby, air in the firststorage chamber 21 is sucked through the suction hole 24 b formed at theupper portion of the left side of the rear surface of the first storagechamber 21, and the sucked air is cooled into low-humidity andlow-temperature air through the evaporator 27 and is discharged to theinside of the first storage chamber 21 through the discharge hole 25 bformed at the lower portion of the right side of the rear surface of thefirst storage chamber 21.

Then, the control unit 52 counts time for which the first and seconddampers 45 and 46 are driven so that the air channel of the first duct41 is opened (Operation 310), and judges whether or not a designatedtime has elapsed (Operation 312).

As a result of the judgment of Operation 312, if the designated time hasnot elapsed, the process is fed back to Operation 310, the control unit52 counts time until the designated time has elapsed.

On the other hand, as the result of the judgment of Operation 312, ifthe designated time has elapsed, the process is fed back to Operation302 and the control unit 52 drives the first and second dampers 45 and46 through the damper drive unit 56 so that the air channel of thesecond duct 41 is opened.

Through the above method, air flows in the upward direction, flows inthe downward direction and then flows in the upward direction and thusthe roles of the suction holes 24 a and 24 b and the discharge holes 25a and 25 b are periodically interchanged. Thereby, cool air in the firststorage chamber 21 is uniformly distributed and thus the temperaturewithin the first storage chamber 21 is uniformly maintained.

As is apparent from the above description, in a refrigerator and acontrol method thereof in accordance with one embodiment of the presentinvention, roles of suction and discharge holes are interchanged invarious manners under various conditions so as to uniformly distribute acool air flow in a storage chamber, thereby preventing localsupercooling and uniformly maintaining the internal temperature of thestorage chamber.

Although a few embodiments have been shown and described, it would beappreciated by those skilled in the art that changes may be made inthese embodiments without departing from the principles and spirit ofthe invention, the scope of which is defined in the claims and theirequivalents.

1. A refrigerator comprising: a storage chamber; an evaporator to coolair in the storage chamber; a first opening to suck the air in thestorage chamber; a second opening to discharge the air cooled by theevaporator to the inside of the storage chamber; a fan provided withblades, which are driven at a first angle and a second angle; and acontrol unit to adjust the direction of a flow of the air by driving thefan at the first angle so that the air in the storage chamber is suckedthrough the first opening and is then discharged to the inside of thestorage chamber through the second opening and by driving the fan at thesecond angle so that the air in the storage chamber is sucked throughthe second opening and is then discharged to the inside of the storagechamber through the first opening.
 2. The refrigerator according toclaim 1, wherein the first angle and the second angle are blade angleshaving reverse delta values.
 3. The refrigerator according to claim 2,wherein the control unit drives the fan at the first angle or the secondangle so as to periodically change the direction of the air flow.
 4. Arefrigerator comprising: a storage chamber; an evaporator to cool air inthe storage chamber; a first opening to suck the air in the storagechamber; a second opening to discharge the air cooled by the evaporatorto the inside of the storage chamber; first and second fans torespectively generate flows of the air in opposite directions; and acontrol unit to adjust the direction of the air flow by driving thefirst fan so that the air in the storage chamber is sucked through thefirst opening and is then discharged to the inside of the storagechamber through the second opening and by driving the second fan so thatthe air in the storage chamber is sucked through the second opening andis then discharged to the inside of the storage chamber through thefirst opening.
 5. The refrigerator according to claim 4, wherein thefirst fan and the second fan have blade angles having reverse values. 6.The refrigerator according to claim 5, wherein the control unit drivesthe first and second fans so as to periodically change the direction ofthe air flow.
 7. A refrigerator comprising: a storage chamber; anevaporator to cool air in the storage chamber; a pair of first openingsto suck the air in the storage chamber; a pair of second openings todischarge the air cooled by the evaporator to the inside of the storagechamber; first and second ducts respectively connecting the pair offirst openings and the pair of second openings to form air channels inthe storage chamber; first and second dampers installed in the first andsecond ducts to permit or block the air flow toward one of the first andsecond ducts; and a control unit to adjust the direction of the air flowby controlling the first and second dampers so that the air flows towardone of the first and second ducts.
 8. The refrigerator according toclaim 7, wherein the first and second dampers are installed at anintersection between the first and second ducts.
 9. The refrigeratoraccording to claim 8, wherein the control unit drives the first andsecond dampers so as to periodically change the direction of the airflow.
 10. The refrigerator according to claim 7, further comprising athird duct at which the first duct and the second duct meet, wherein theevaporator and a fan are installed in the third duct.
 11. Therefrigerator according to claim 7, wherein the pair of first openingsand the pair of second openings are respectively installed at upper andlower portions of the rear surface of the storage chamber.
 12. Therefrigerator according to claim 7, wherein the pair of first openingsand the pair of second openings are respectively installed at both sidesurfaces of the storage chamber.
 13. A control method of a refrigerator,which has a storage chamber, a first opening to suck the air in thestorage chamber, a second opening to discharge the air to the inside ofthe storage chamber, and a fan provided with blades, the angle of whichis varied, to generate a flow of the air, comprising: driving the fan ata first angle of the blades so that the air in the storage chamber issucked through the first opening and is then discharged to the inside ofthe storage chamber through the second opening; judging whether or not adesignated time has elapsed; and driving the fan at a second angle ofthe blades so that the air in the storage chamber is sucked through thesecond opening and is then discharged to the inside of the storagechamber through the first opening, upon judging that the designated timehas elapsed.
 14. The control method according to claim 13, wherein thedriving of the fan at the first angle of the blades and the driving ofthe fan at the second angle of the blades are periodically alternated soas to uniformly distribute the air flow throughout the overall space ofthe storage chamber.
 15. A control method of a refrigerator, which has astorage chamber, a first opening to suck the air in the storage chamber,a second opening to discharge the air to the inside of the storagechamber, and first and second fans to respectively generate flows of theair in opposite directions, comprising: driving the first fan so thatthe air in the storage chamber is sucked through the first opening andis then discharged to the inside of the storage chamber through thesecond opening; judging whether or not a designated time has elapsed;and driving the second fan so that the air in the storage chamber issucked through the second opening and is then discharged to the insideof the storage chamber through the first opening, upon judging that thedesignated time has elapsed.
 16. The control method according to claim15, wherein the driving of the first fan and the driving of the secondfan are periodically alternated so as to uniformly distribute the airflow throughout the overall space of the storage chamber.
 17. A controlmethod of a refrigerator, which has a storage chamber, a pair of firstopenings to suck the air in the storage chamber, a pair of secondopenings to discharge the air to the inside of the storage chamber,first and second ducts respectively connecting the pair of firstopenings and the pair of second openings to form air channels in thestorage chamber, and first and second dampers installed in the first andsecond ducts to permit or block the air flow toward one of the first andsecond ducts, comprising: driving the first and second dampers so thatthe air flows toward one of the first and second ducts; judging whetheror not a designated time has elapsed; and driving the first and seconddampers so that the air flows toward the other one of the first andsecond ducts, upon judging that the designated time has elapsed.
 18. Thecontrol method according to claim 17, wherein the driving of the firstand second dampers so that the air flows toward one of the first andsecond ducts and the driving of the first and second dampers so that theair flows toward the other one of the first and second ducts areperiodically alternated so as to uniformly distribute the air flowthroughout the overall space of the storage chamber.